Generating multi-atom entangled W states via light-matter interface based fusion mechanism

W state is a key resource in quantum communication. Fusion technology has been proven to be a good candidate for preparing a large-size W state from two or more small-size W states in linear optical system. It is of great importance to study how to fuse W states via light-matter interface. Here we show that it is possible to prepare large-size W-state networks using a fusion mechanism in cavity QED system. The detuned interaction between three atoms and a vacuum cavity mode constitute the main fusion mechanism, based on which two or three small-size atomic W states can be fused into a larger-size W state. If no excitation is detected from those three atoms, the remaining atoms are still in the product of two or three new W states, which can be re-fused. The complicated Fredkin gate used in the previous fusion schemes is avoided here. W states of size 2 can be fused as well. The feasibility analysis shows that our fusion processes maybe implementable with the current technology. Our results demonstrate how the light-matter interaction based fusion mechanism can be realized, and may become the starting point for the fusion of multipartite entanglement in cavity QED system.Comment: 9 pages, 2 figure

Constraining Neutrino Cosmologies with Nonlinear Reconstruction

Nonlinear gravitational evolution induces strong nonlinearities in the observed cosmological density fields, leading to positive off-diagonal correlations in the power spectrum covariance. This has caused the information saturation in the power spectrum, e.g., the neutrino mass constraints from the nonlinear power spectra are lower than their linear counterparts by a factor of $\sim2$ at $z=0$. In this paper, we explore how nonlinear reconstruction methods improve the cosmological information from nonlinear cosmic fields. By applying nonlinear reconstruction to cold dark matter fields from the Quijote simulations, we find that nonlinear reconstruction can improve the constraints on cosmological parameters significantly, nearly reaching the linear theory limit. For neutrino mass, the result is only $12\%$ lower than the linear power spectrum, i.e., the theoretical best result. This makes nonlinear reconstruction an efficient and useful method to extract neutrino information from current and upcoming galaxy surveys.Comment: 14 pages, 8 figures, accepted versio

catena-Poly[[[aqua­(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)zinc]-μ-3-chloro­benzene-1,2-dicaboxylato-κ2 O 2:O 3] [[(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)zinc]-μ-3-chloro­benzene-1,2-dicaboxylato-κ2 O 2:O 3]]

In the title compound, {[Zn(C8H3ClO4)(C12H12N2)(H2O)]·[Zn(C8H3ClO4)(C12H12N2)]}n, one Zn2+ ion is five-coordin­ated by two O atoms from two different 3-chloro­benzene-1,2-dicarboxyl­ate ligands, one O atom from a water mol­ecule and two N atoms from a 4,4′-dimethyl-2,2′-bipyridine ligand, while the second Zn2+ ion is four-coordinated by two O atoms from two different 3-chloro­benzene-1,2-dicarboxyl­ate ligands, and two N atoms from a 4,4′-bimethyl-2,2′-bipyridine ligand. The crystal structure exhibits a three-dimensional supra­molecular structure composed of alternate Zn(C8H3O4Cl)(C12H12N2) and Zn(C8H3O4Cl)(C12H12N2)(H2O) chains, which are linked together by face-to-face π–π inter­actions [shortest centroid–centroid distances of 3.661 (4) and 3.6901 (3) Å], O—H⋯O and C—H⋯O hydrogen bonds

Effect of Lactobacillus acidophilus M6 on Improving Exercise Performance and Relieving Fatigue in Mice

Objective: To isolate Lactobacillus acidophilus M6 from the feces of long-distance runners in the early stage. The aim of this study was to investigate the effect of Lactobacillus acidophilus M6 on improving exercise ability and alleviating fatigue function in mice. Methods: Sixty C57BL/6N male mice were randomly divided into 4 groups: Control, low, medium and high dose groups of L. acidophilus M6, L. acidophilus M6 was given daily for four weeks, muscle strength, exercise endurance, fatigue related indicators, energy related indicators and antioxidant related indicators were measured. Results: The low, medium and high dose of L. acidophilus M6 significantly (P<0.001) improved the forelimb grip strength (124.01±6.02, 132.02±4.30 and 139.66±4.72 g) and exhaustive swimming time (8.03±1.05, 10.06±1.10 and 14.36±0.55 min). The low, medium and high dose of L. acidophilus M6 significantly (P<0.001) reduced the fatigue indexes including the creatine kinase activity (730.66±16.77, 647.66±39.95 and 594.56±32.33 U/L), serum lactic acid (10.13±1.00, 8.36±0.99 and 6.09±0.36 mol/L), serum urea nitrogen (6.40±0.53, 5.96±0.85 and 5.23±0.25 nmol/L) and blood ammonia (115.34±4.50, 99.67±4.50 and 94.33±4.72 μmol/L). L. acidophilus M6 significantly (P<0.001) improved energy metabolism indexes including increasing blood glucose, muscle glycogen and liver glycogen, and significantly (P<0.001) reducing triglyceride content in a dose-dependent manner. L. acidophilus M6 significantly (P<0.001) increased the activity of serum superoxide dismutase, catalase and glutathione peroxidase and decreased the content of malondialdehyde in mice in a dose-dependent manner at the range from 3×107 CFU to 3×109 CFU. Conclusion: L. acidophilus M6 could improve exercise performance and relieve fatigue after exercise in mice by improving the grip strength of forelimbs and the exhaustion swimming time, and increase the indexes related to energy metabolism and antioxidant capacity by decreasing the fatigue indexes such as creatine kinase activity, lactic acid, urea nitrogen and blood ammonia

Novel Constructions of Mutually Unbiased Tripartite Absolutely Maximally Entangled Bases

We develop a new technique to construct mutually unbiased tripartite absolutely maximally entangled bases. We first explore the tripartite absolutely maximally entangled bases and mutually unbiased bases in $\mathbb{C}^{d} \otimes \mathbb{C}^{d} \otimes \mathbb{C}^{d}$ based on mutually orthogonal Latin squares. Then we generalize the approach to the case of $\mathbb{C}^{d_{1}} \otimes \mathbb{C}^{d_{2}} \otimes \mathbb{C}^{d_{1}d_{2}}$ by mutually weak orthogonal Latin squares. The concise direct constructions of mutually unbiased tripartite absolutely maximally entangled bases are remarkably presented with generality. Detailed examples in $\mathbb{C}^{3} \otimes \mathbb{C}^{3} \otimes \mathbb{C}^{3},$ $\mathbb{C}^{2} \otimes \mathbb{C}^{2} \otimes \mathbb{C}^{4}$ and $\mathbb{C}^{2} \otimes \mathbb{C}^{5} \otimes \mathbb{C}^{10}$ are provided to illustrate the advantages of our approach

Mutually unbiased maximally entangled bases from difference matrices

Based on maximally entangled states, we explore the constructions of mutually unbiased bases in bipartite quantum systems. We present a new way to construct mutually unbiased bases by difference matrices in the theory of combinatorial designs. In particular, we establish $q$ mutually unbiased bases with $q-1$ maximally entangled bases and one product basis in $\mathbb{C}^q\otimes \mathbb{C}^q$ for arbitrary prime power $q$. In addition, we construct maximally entangled bases for dimension of composite numbers of non-prime power, such as five maximally entangled bases in $\mathbb{C}^{12}\otimes \mathbb{C}^{12}$ and $\mathbb{C}^{21}\otimes\mathbb{C}^{21}$, which improve the known lower bounds for $d=3m$, with $(3,m)=1$ in $\mathbb{C}^{d}\otimes \mathbb{C}^{d}$. Furthermore, we construct $p+1$ mutually unbiased bases with $p$ maximally entangled bases and one product basis in $\mathbb{C}^p\otimes \mathbb{C}^{p^2}$ for arbitrary prime number $p$.Comment: 24 page

Quantum kk-uniform states from quantum orthogonal arrays

The quantum orthogonal arrays define remarkable classes of multipartite entangled states called $k$-uniform states whose every reductions to $k$ parties are maximally mixed. We present constructions of quantum orthogonal arrays of strength 2 with levels of prime power, as well as some constructions of strength 3. As a consequence, we give infinite classes of 2-uniform states of $N$ systems with dimension of prime power $d\geq 2$ for arbitrary $N\geq 5$; 3-uniform states of $N$-qubit systems for arbitrary $N\geq 6$ and $N\neq 7,8,9,11$; 3-uniform states of $N$ systems with dimension of prime power $d\geq 7$ for arbitrary $N\geq 7$.Comment: 26 pages, 1 figure

Investigations on the effectiveness of protection methods for a submarine pipeline exposed to the impact of a falling anchor

The occurrence of a buried submarine pipeline crossing a channel becoming damaged by the impact of a falling anchor is becoming more common. It is important to analyze the dynamic response of pipelines exposed to such impact and develop effective protection methods to ensure the safe operation of the pipelines exposed to the impact of falling anchors. In this study, different protection methods, including pure rock, concrete mattress + rock, concrete mattress + rock + rubber pad, and compound flexible pad + rock, are physically tested. The strains at the impacting point and along the pipeline were measured with the fiber Bragg grating (FBG) sensors. The effectiveness of the protection methods is analyzed based on the maximum strain and its affected length on the pipeline. Then, a theoretical model is established to analyze the deformation and strain of a pipeline. Through curve-fitting the experimental results, the bearing capacity coefficients for different protection methods are determined. The protection method of compound flexible pad + rock has the best performance to protect the pipeline from the impact of a falling anchor

Numerical simulation analysis of large eddy simulation for T-tube based on solid-liquid two-phase abrasive flow

As a kind of nano machining technology, abrasive flow polishing technology plays an important role in precision machining region. As an important numerical simulation method in fluid mechanics, large eddy numerical simulation method has become an important method for many scholars to study abrasive grain polishing technology. In this paper, the use of fluid mechanics software FLUENT and selected Mixture mixed model. Based on the theory of solid-liquid two-phase flow dynamics, the large-eddy numerical simulation method was used to study the polishing process of T-tube abrasive flow, and the micro-machining mechanism of abrasive-polished workpiece was discussed. The influence of the different inlet velocities on the polishing effect of the abrasive grains was discussed by analyzing the numerical simulation results of the different inlet velocities of the abrasive grains during the processing of the T-tube

Numerical analysis for viscosity temperature characteristics of abrasive flow finishing on micro-bore nozzle

Abrasive flow machining has become an efficient and economical ultra precision process for machining micro-bore parts. In this paper, aiming at viscosity temperature characteristics of abrasive flow finishing on micro-bore nozzle, under the guidance of the three governing equations of fluid mechanics theory, mixed phase model and discrete phase model were conducted, FLUENT software was resorted to simulate the discrete and fluid phase numerical characteristics of the solid-liquid two-phase flow field in the nozzle orifice with various field temperature and viscosity of slurry, the mechanism of erosion and wear of particles and effect of different processing parameters on particle erosion rate were uncovered, which provides a theoretical basis for the nozzle structure of abrasive flow machining